The medical profession uses disposable medical electrodes in a variety of ways during the caring of patients. For example, disposable electrodes are used in the performance of such therapeutic and diagnostic functions as patient defibrillation, external cardiac pacing and ECG monitoring. Generally, the disposable electrodes are maintained in contact with the patient's skin by a self-sticking adhesive and are connected to an appropriate medical apparatus by a cable. Appropriate electric signals are transmitted between the electrode and the medical apparatus via the cable. Normally, the cable has a female connector on one end for connecting the cable to the electrode and a male connector on the other end for connecting the cable to the appropriate medical apparatus. The electrodes generally have a male connector (i.e., a post) that can be engaged by the female connector on the end of the cable.
To prevent connecting the wrong cables to the wrong electrodes, such as connecting a defibrillation cable to a pacing electrode, for example, each of the different types of prior art electrodes is equipped with a different shaped post. More specifically, the post on a prior art defibrillation electrode is different than the post on a prior pacing electrode, and both posts are different from the post on a prior art ECG electrode. The female connectors on the different types of cables are matched to the appropriate electrodes and, as a result, are also different from one another. Consequently, in the prior art, an ECG cable can only be connected to an ECG electrode, a defibrillation cable can only be connected to a defibrillation electrode, and a pacing cable can only be connected to a pacing electrode. Thus, by making the male-to-female connections different for each type of electrode, the prior art provides safe patient treatment by preventing the wrong cable from being connected to the wrong electrode. Obviously, such an improper connection could threaten the health of a patient.
The importance of the different types of connections for the different types of electrodes is especially apparent when more than one type of electrode is used on a particular patient. For example, it is a common medical practice to monitor a patient's condition after the patient has been defibrillated. To accomplish this in the prior art, medical personnel must, after defibrillation, remove the defibrillation electrodes from the patient and attach ECG monitoring electrodes to the patient. For the reasons noted above, the defibrillation electrodes are connected to defibrillation cables and the ECG electrodes are connected to ECG cables. If the patient needs to be defibrillated again, such as when the patient's ECG rhythm is absent, the medical personnel must remove the ECG electrodes and attach new defibrillation electrodes to the patient. The ECG electrodes are removed during defibrillation to make room for the defibrillation electrodes and to prevent injury to personnel or damage to equipment that may be connected to the ECG electrodes when the patient is defibrillated. Once the defibrillation and ECG electrodes are removed from a patient, they are normally discarded for such reasons as personal hygiene and to ensure that an electrode that may have been damaged during removal is not reused on a patient. Such a prior art procedure wastes valuable time and is costly, considering the time it takes medical personnel to remove and reattach the electrodes and the cost of the electrodes themselves.
As can be readily appreciated from the foregoing discussion, there has developed a need in the medical profession for a discriminating medical electrode connector, whereby a disposable defibrillation electrode can be used, at separate times, for defibrillation and ECG monitoring of the same patient. Such a discriminating connector should also offer patient safety be preventing the connection of a defibrillation cable to an ECG monitoring electrode which might permit an inadvertent defibrillation of the patient to be attempted through use of the ECG monitoring electrode. The present invention provides these results.